Cypriniformes I (Minnows and Carps)

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Cypriniformes I

(Minnows and carps)

Class Actinopterygii

Order Cypriniformes

Number of families 1 of minnows and carps


Evolution and systematics

Cypriniforms are typical freshwater fishes in which the upper jaw is usually protractile; the mouth (jaws and palate) is always toothless; the adipose fin is absent; the head almost always scaleless; and barbels are either present or absent. These fishes have Weberian ossicles (four small bones and their ligaments connecting the swim bladder to the inner ear for sound transmission). The fifth ceratobranchial is enlarged as the pharyngeal bone, with teeth ankylosed (joined) to it. For cyprinids, pharyngeal teeth are in one to three rows, and there are never more than eight teeth in any one row; for non-cyprinid cypriniforms, pharyngeal teeth are usually greater in number but only in one row.

Generally, Cypriniformes is divided into two monophyletic groups: the family Cyprinidae and the non-cyprinid cypriniforms. The Cyprinidae includes different kinds of minnows and carps. The non-cyprinid cypriniforms are composed of the family Catostomidae (suckers), family Gyrinocheilidae (algae eaters), and many different loaches. The relationships among the non-cyprinid cypriniforms are still in debate. Recent molecular data suggest that suckers could be at the basal position of this group, followed by the algae eaters and then the different loaches. This chapter focuses on the family Cyprinidae.

The recognition and composition of the subfamilies in the Cyprinidae is still in question. Several proposals have been provided based on morphological characters, and the recent molecular data support a combination of them. Thus, 9 subfamilies, forming two phyletic lineages, are recognized. The first lineage consists of subfamilies Cyprininae, Barbinae (including Schizothoracinae), and Labeoninae. The second lineage consists of subfamilies Rasborinae (Danioninae), Leuciscinae, Tincinae, Acheilognathinae, Gobioninae (including Gobiobotinae), and Xenocyprinae (the east Asian group, including Cultrinae, Hypophthalmichthyinae, etc.). All these different subfamilies could have evolved from barbus-like cyprinids, with parallel evolutions of certain characters, such as the loss of three-rowed pharyngeal teeth, loss of barbels, and so on.

The earliest cyprinid fossils are known from South China from the Eocene period, and could represent cyprinini and rasborini; the earliest European and North American ones are of Oligocene age. The cyprinids might have originated in Asia and dispersed to North America through the Bering land bridge and to Europe before the upheaval of the Tibetan Plateau. The earliest record of cyprinids in Africa was in the Miocene period. Cyprinids may have migrated from Southeast Asia to Africa through the Near East during the Miocene.

Physical characteristics

Normally, carps are fusiform or streamlined, with the body somewhat compressed. The dorsal fin is long (in Cyprinus) or short, and the last unbranched fin ray is soft, hard, or spine-like, with serrations on the posterior edge in Cyprininae and some barbinins. Pectoral fins and ventral fins are in the normal position. The anal fin has five soft, branched fin rays in Cyprininae, Barbinae, and Labeoninae species; six in Gobioninae species; and seven or more in other groups. The last unbranched anal fin ray is soft, hard, or spine-like. The caudal fin is forked in all species.

Breams and some cultrin species have a very deep body, which may protect them from predators' bites. Living on the river bottom and adapted to fast running water, most Gobionine species have a round and slender body and are called "stick fish" by fisherman. The head of Luciobrama is strongly elongated, forming a pipe shape.

Most carps and minnows are covered with scales. However, the leather carp, one variation of the common carp, has no scales. Some Schizothoracin fishes are half or completely naked. The sawbwa barb, Sawbwa resplendens, which is endemic to Lake Inle in Myanmar, is completely naked and a little transparent. The lateral line is complete in most species but incomplete in some small fishes, such as Aphyocypris and Rhodeus.

The most common coloration for carps is dark green on the back and whitish on the belly, which makes the fishes difficult to spot both from above the water and under the water. However, color variations are also very common. Some gobio species have different dots; Danio and Zacco species have beautiful stripes; and some barbin species and bitterlings are even more colorful.

The largest species are the tetraploid barbine Catlocarpio siamensis of Thailand, which is known to reach at least 8.2 ft (2.5 m) and probably 9.84 ft (3 m), and Tor putitora of the Brahmaputra River (eastern India), which reaches about 8.86 ft (2.7 m); in North America the Colorado pikeminnow, Ptychocheilus lucius, can reach 5.9 ft (1.8 m); other large Asian species (6.6 ft [2 m] or larger) include Elopichthys bambusa and Barbus esocinus. The smallest cyprinid is Danionella translucida, distributed in Burma, in which females are mature at about 0.4–0.43 in (10–11 mm) and the longest specimen known is 0.47 in (12 mm).

Distribution

Cyprinidae is the largest family of freshwater fishes, with about 210 genera and about 2,010 species. Of this figure, about 1,270 species are native to Eurasia (the greatest generic diversity and number of species is in China and Southeast Asia; China alone contains about 532 species in 132 genera); about 475 species in 23 genera are native to Africa; and about 270 species in 50 genera are native to North America. In North America there are only phoxinine species, while in Europe there are mainly leuciscine species in addition to one species of bitterling, the monotypic Tinca, some Gobio species,

and some Barbus species. In Africa there are only three subfamilies present: barbine, labeonine, and rasborine. In East Asia, especially China, all types are distributed. The specialized schizothoracine fishes are mainly found in and around the Tibetan Plateau.

Habitat

Carps can live in a large variety of habitats, from small streams and ponds to large rivers and lakes. Almost all carps live in freshwaters, although the European roach and bream (Rutilus and Abramis, respectively) have populations in the brackish part of the Baltic Sea; the Japanese Tribolodon spends part of its life at sea; and the Chinese carp Cyprinus acutidorsalis can live in the river mouth of Qingjiang River near Vietnam. Phoxinus and gudgeons like to stay in small streams. Big fishes like Elopichthys bambusa are mainly found in large rivers. Danio species must live in waters with temperatures higher than 64.4°F (18°C), while Leuciscus species only live in cold waters (39.2–71.6°F [4–22°C]). Garra and Labeo species like to adhere to the bottoms of streams and rivers with fast running water. Bitterlings prefer still or slow running waters such as ponds and lakes. Culter fishes often swim in the upper parts of waters or near the surface to catch insects, but the common carp and crucian carp mainly stay at the bottom sucking worms.

Behavior

Cyprinid fishes have good vision, including color vision, and use visual displays. The use of pheromones in cyprinid social communication is well established. For instance, they have an ability called fright reaction. When threatened by a predator, an individual may release alarm substances through specialized goblet or club cells in the skin. These secretions cause the other fishes nearby to disperse and hide. In this way, the rest of the group can avoid the predator. Cyprini-form fishes also have excellent hearing. Shoaling minnows find food more quickly in groups and are less vulnerable to

predation. Though some species like to search for food solitarily, in the spring they may form schools for reproduction, and in fall or winter they may transfer to deeper water as water levels decline.

Some species exhibit territorial behavior. For example, in breeding season, the male of the bitterling species, Rhodeus ocellatus, may find a good mussel and protect the area around this mussel as his territory.

Living only in freshwater, cyprinids need not migrate between fresh and marine waters. But some species can swim for very long distances (up to 1,012 mi [1,629 km]). Some East Asian groups undergo river and lake migration. These fishes spawn in the middle or upper reaches of rivers when heavy flood occurs. Their eggs float with the running water and hatch. The fries also float with the running water in the first few days after hatching, before running into lakes that connect to the rivers. The young fish then may stay in the lakes to take advantage of the abundance of food. When they mature, they will migrate to the rivers to breed.

Feeding ecology and diet

Cyprinids comprise a wide variety of specialists and generalists feeding on all trophic levels. Most feed on secondary producers: zooplankton, crustaceans, larvae, pupae and adults of insects, oligochaetes, bryozoans, snails, and mussels. Some also consume primary (macrophytes and phytoplankton) or tertiary (fishes) producers. According to feeding behavior, cyprinids can be categorized into three modes: herbivores, pelagic feeders, and benthic feeders. Herbivores like grass carp eat not only aquatic plants but also the land grasses submerged by flood water. Condrostoma and Xenocypris, for example, use the horny edge on their lower jaws to scrape the algae on the bottom. Pelagic feeders mainly catch zooplankton and surface insects, but Elopichthys bambusa and the Colorado pikeminnow are very ferocious and feed on fishes. Some species, like silver carp and bighead carp, have evolved special gill organs for filtering plankton. Pectenocypris balaena of the Kapuas River in Borneo has up to at least 212 gill rakers for filtering phytoplankton. Benthic feeders suck in the sediment particles together with the organisms and separate the

organisms in the pharyngeal slit. Sediment particles pass through the sieve, whereas food organisms are retained. Substratum particles too large to pass the basket are spit out.

None of the cyprinids are strictly monophagous, but many may feed on only one type of food organism, depending on

availability. The feeding of European cyprinids includes all diets and feeding modes. The cyprinids from Asia seem to have the greatest variety in feeding specialists with both small and large species, whereas the cyprinids in North America have the smallest variety. Cyprinids in Africa are comprise a relatively small variety of feeding types.

There is an interesting ontogenetic switch of the feeding mode in cyprinids. Almost all cyprinids start to feed on plankton shortly after hatching. As individuals increase in size, their prey choice changes, and they differentiate into the specialized feeding modes (herbivore, piscivore, and benthivore).

Reproductive biology

Carps and minnows mostly spawn in spring and summer, because the larvae will get food easily. One bitterling species breeds in autumn, which is an alternative strategy. The water temperature for reproduction may be as low as 44.6–48.2°F (7–9°C) for cold water species but must be above 64.4°F (18°C) for most East Asian groups. During breeding season, the males usually have beautiful color, for example an orange tail or anal fin to stimulate or attract females. Some species may have tubercles on the head or pectoral fin called

pearl organs, which can be used to provide tactile stimulation during courtship by pushing the female.

Usually, when their conditions are suitable, the males chase the females and press up against their abdomens. During this activity the fishes swim at very high speeds. The females then lay eggs, and the males release their sperm. Environmental conditions that impact fertilization include water temperature as well as the nature of the substances that the eggs adhere to, whether they are aquatic plants, stones, or other substances. Grass carp only spawn after heavy floods and when the water temperature is above 64.4°F (18°C); the flood surge is needed to carry eggs and larvae. Otherwise, the eggs may sink to the bottom and die.

Some cyprinids have adopted unusual breeding habits. A small minnow in southwestern China, Gobiocypris rarus, pushes the eggs to adhere to walls above water level through the beating of its tail. The female bitterling species lay their eggs into the gill chambers of mussels through a long tube (ovipositor).

In breeding season, the males of North American minnow known as the stoneroller dig spawning pits by driving their heads into the gravel. They transport gravel from the pits by nudging stones out with their snouts, or by transporting them with their mouths. The males compete aggressively for favored spawning areas. Male fathead minnows select nest sites under rocks or logs and they excavate the area to increase the available space, and then defend the nests aggressively from all other fatheads. After the female lays her sticky eggs on the underside of the nest object, the male fertilizes the eggs and guards the incubating eggs. He even fans them with his fins and massages them with his back pad to keep them clean and well oxygenated.

Spawning minnows of some species of Luxilus, Cyprinella, Notemigonus, and Notropis use the nests of other species of cyprinids or of species of the family Centrarchidae to deposit their eggs and leave the embryos to the protection of the host.

Many species spawn only one time in a single breeding season, but some species (e.g., common carps, the bitterling

fishes) have developed a strategy to spawn more than one time in a breeding season. Some species can even spawn for the whole year at an interval of 3 to 15 days.

The eggs of many species are adhesive, sticking to stones or aquatic plants. Eggs are semi-pelagic in some East Asian groups (grass carp, silver carp): the eggs sink to the bottom in still water but float with the current in running water.

The duration of development differs from species to species depending on water temperature. At 44.6°F (7°C), roach eggs take 30 days to hatch and dace eggs take 44 days. At 59°F (15°C), by contrast, only 14 days are needed for dace eggs to hatch. When temperature is 68–77°F (20–25°C), common carp eggs take 2.5–3 days to hatch. For the first few days after hatching, the larvae can not swim. Several days later, the air-bladder begins to fill with air, the yolk-sac is nearly gone,

and the larva begins to swim freely and catch food, usually plankton.

Conservation status

The IUCN Red List contains 252 species of cyprinids. Of these, 15 are categorized as Extinct; 1 as Extinct in the Wild; 39 as Critically Endangered; 31 as Endangered; 89 as Vulnerable; 6 as Lower Risk/Conservation Dependent; 23 as Lower Risk/Near Threatened; and 48 as Data Deficient. Of the 15 extinct species, 12 are from the Americas, 1 from East Asia, 1 from the Middle East, and 1 from Europe.

Major threats to cyprinids are habitat destruction, such as the construction of dams that cut off the migration routes; the eutrophication in lakes that destroys the aquatic plants necessary for cyprinid spawning; and the decrease of water area due to economic development. In addition, overfishing and competition for water resources with agricultural irrigation are also important factors threatening cyprinids. In recent years, the threat due to the introduction of exotic non-native species has become more serious.

Significance to humans

Cyprinids are an important food fish. According to an FAO (Food and Agriculture Organization of the United Nations) production report for the year 1996, there were 4 cyprinid species among the top 10 species or species groups: silver carp, grass carp, common carp, and bighead carp. Cyprinids are also important in sport fishing, especially the barbel in Europe and the common carp, crucian carp, and grass carp in Asia. One cyprinid, the zebrafish, has become one of the most important model fishes in genetics and medical research.

Many cyprinids are important aquarium pets. Good examples are goldfish, zebrafish, and other danios, small barbs, rasboras, and bitterlings. The Japanese colored carp, koi, is cultured in ponds as an ornamental fish. After many years of selection, the Japanese koi and Chinese goldfish have become very different from their wild types.

Grass carp have been introduced to many countries to control aquatic vegetation. Phytoplankton eaters such as the silver carp, have been used to control eutrophication in some countries. However, the introduction of carp species has also had negative effects, including the destruction of native fish fauna because of the competition for food and/or habitat changes, such as the decrease of aquatic vegetation.

Species accounts

List of Species

Barbel
Stoneroller
Crucian carp
Grass carp
Upper mouth
Common carp
Zebrafish
Black stick
Gudgeon
Silver carp
Ningu
Common dace
Eurasian minnow
Fathead minnow
Colorado pikeminnow
Tiger barb
Harlequin
Dagaa
Rosy bitterling
Rudd
Schizothorax prenanti
Tench
Smallscale yellowfin

Barbel

Barbus barbus

family

Cyprinidae

taxonomy

Cyprinus barbus Linnaeus, 1758, Europe.

other common names

French: Barbet; German: Barbern.

physical characteristics

Size large, usually up to 29.92 in (76 cm) in length. Body long. Snout pointed. Mouth inferior. Lips fleshy. Barbels 2 pairs. Pharyngeal teeth in three rows. Dorsal fin with 4 unbranched, 7–9 branched rays; anal fin with 3 unbranched, 5 branched rays. Lateral line complete, with 56–65 scales. Vertebrae 46–47. Brown-green above, green-yellow lower sides, white-yellow belly. Covered with dark-brown spots.

distribution

West and Central Europe excluding Italian, Greek and Iberian peninsulas.

habitat

Deep, fast-flowing upper reaches of rivers with stony or gravel bottoms (barbel zones). Common temperature is 59–71.6°F (15–22°C).

behavior

Barbels normally occur in groups of several individuals close to the river bed, but they do not congregate in schools. They migrate in rivers with a home range of 1.24–12.43 mi (2–20 km).

feeding ecology and diet

Feeds chiefly on benthic invertebrates such as small crustaceans, insect larvae, mollusks, mayfly and midge larvae, and small fishes.

reproductive biology

Males mature in the fourth year and females in the fifth year of life. After the fish have migrated upriver, spawning occurs from May to July when water temperature is 57.2–68°F (14–20°C) and the bottom is filled with sand and pebbles. Eggs are firmly attached to stones. Fecundity is 8,000–12,000 eggs per kilogram of body weight.

conservation status

Not listed by IUCN.

significance to humans

An important food fish and sport fish, particularly in Europe.


Stoneroller

Campostoma anomalum

family

Cyprinidae

taxonomy

Rutilus anomalous Rafinesque, 1820, Licking River, Kentucky, Ohio River drainage, United States.

other common names

English: Central stoneroller, largescale stoneroller.

physical characteristics

Size small to moderate, maximum 7.87 in (20 cm) in total length. Body stout and moderately compressed, with the nape

region becoming swollen and prominent in adults. Snout bluntly rounded and projecting beyond the nearly horizontal mouth. Lower jaw has spade-like extension. Scales deep, rather small, and crowed anteriorly; more or less mottled with dark background; scales in lateral line 53. Dorsal fin with 8 branched rays; anal fin with 7 branched rays. Color brownish, with a brassy luster above. Dusky vertical bar behind the opercle; dorsal and anal fins each with a dusky crossbar about half way up, the rest of the fin is olive in females and fiery red in males in spring. In the spring, the head and sometimes the entire body of males are covered with large rounded tubercles.

distribution

North America, widespread across most of eastern and central United States in Atlantic, Great Lakes, Mississippi River, and Hudson Bay basins from New York west to North Dakota and Wyoming and south to South Carolina and Texas; Thames River system in Canada; from Galveston Bay in Texas to Rio Grande in Mexico.

habitat

Moderate to high gradient streams with sandy to gravely substrate. Prefers riffle areas where riffles and pools alternate in rapid succession. However, can survive in almost any stream with a food supply.

behavior

Shoaling species.

feeding ecology and diet

Primarily herbivorous, feeding diurnally on filamentous algae and diatoms but also taking detritus and aquatic insects from the periphyton assemblage on rock surfaces. Because of its long intestine (up to 8 times its body length), this species is incredibly efficient at digesting detritus and algae.

reproductive biology

Matures in second or third summer of life. Adults spawn between March and late May, when water temperatures are from 55.4–80.6°F (13–27°C). Males dig spawning pits in shallow, swift riffles and occasionally in quiet pools by driving their heads into the gravel. They transport gravel from the pits by nudging stones out with their snouts (hence the name stoneroller) or by transporting them with their mouths. Males compete aggressively for favored spawning areas. Females remain in deeper water near the spawning pits and enter the pits individually or in groups to deposit eggs. The adhesive eggs become lodged in the gravel and are abandoned prior to hatching.

conservation status

Not listed by IUCN.

significance to humans

Not sought by anglers. They do make good bait but are difficult to culture.


Crucian carp

Carassius auratus

family

Cyprinidae

taxonomy

Cyprinus auratus Linnaeus, 1758, China, Japanese rivers.

other common names

English: Goldfish, golden carp.

physical characteristics

Size small to moderate, normally 5.12–7.48 in (13–19 cm) in standard length. Body deep and stout, moderately compressed. Snout pointed. Mouth terminate, oblique. Barbels absent. Pharyngeal teeth in one row. Gill rakers 37–43. Dorsal fin long, 4 spines, 15–19 rays. Anal fin short, 3 spines, 5 rays. Back of last dorsal and anal spines serrated. Lateral line complete, with 27–30 scales. Wild forms are usually olive-green in the back, gray-white on belly.

There are many aquarium varieties in different forms and colors. These can be divided into four types: (1) Grass type: primitive with slender body, pointed head, small eyes, and single or double tails; (2) Fancy type, with double tails and all fins very long; (3) Dragon or Eye type, with large eyes that protrude out; (4) Egg-shaped type, with the dorsal fin absent.

distribution

Native to Asia. The wild type has been introduced to Europe and North America. Aquarium varieties have been introduced all over the world.

habitat

Shallow, warm waters with dense vegetation such as lakes, reservoirs, and streams. Adults are generally found near the bottom, but they sometimes appear in schools at the surface.

behavior

The social behavior of crucian carp is similar to that of the common carp, but under some conditions it can attain a greater population density.

feeding ecology and diet

Omnivorous, consuming a variety of larvae and aquatic insects, mollusks, crustaceans, aquatic worms, and aquatic vegetation.

reproductive biology

The crucian carp matures after the body length reaches 3.54 in (9 cm) in the first or second year. Spawning occurs in spring when the water temperature reaches 60.08°F (15.6°C) and heavy rains occur. The eggs are released in batches, and are usually attached to aquatic plants and other fixed objects. The male fertilizes the eggs immediately. The incubation may take 4 days at 62.6–66.2°F (17–19°C). After hatching, the larvae cling to plants or remain quietly on the bottom, but after 1–2 days they become free-swimming. Fecundity varies from 12,000 to 28,000 eggs per individual.

conservation status

Not listed by the IUCN. Due to artificial hybridization and transplantation, local types have been seriously damaged.

significance to humans

An important food fish, although its production is much less than that of the common carp. Its greatest value is as an aquarium fish.


Grass carp

Ctenopharyngodon idellus

family

Cyprinidae

taxonomy

Leuciscus idella Cuvier and Valenciennes, 1844, China.

other common names

English: White amur; French: Amour blanc; German: Graskarpfen; Spanish: Carpa herbivora.

physical characteristics

Size large, commonly 9.84–35.43 in (25–90 cm) in body length. Body long, cylindrical in the front, compressed in the hind. Belly round. Snout short and blunt. Mouth terminal, large and wide. Barbels absent. Pharyngeal teeth in 2 rows, larger ones compressed like a comb. Gill rakers 14–18. Dorsal fin short, with 3 unbranched, 7 branched rays. Anal fin with 3 unbranched, 8–9 branched rays. Scales moderate, lateral line complete, with 35–42 scales. Coloration brassy olive above, white on lower sides and belly. Edge of scales dark gray. Pectoral and ventral fins gray-yellow, other fins gray.

distribution

East Asia, from Amur River to Yellow River, Yangtze River, and Pearl River. Widely transported around the world.

habitat

Lakes, ponds, pools, and backwaters of large rivers. Prefers large, slow-moving or standing water bodies with vegetation.

behavior

Usually stay in lower depths and are solitary in nature. They mature in lakes and migrate to rivers for reproduction.

feeding ecology and diet

Mainly feeds on aquatic plants and submerged land grasses; also takes detritus, insects, and other invertebrates.

reproductive biology

Grass carps usually mature in the fourth year of life. Spawning occurs in late April and early May, when water temperatures reach 64.4°F (18°C), and with the onset of heavy floods. Mature fishes swim upstream. When the water level rises suddenly, males may chase females and push them. The females then lay eggs, and males release sperm. The eggs are semi-pelagic, floating with the currents. Incubation may take 35–40 hours when temperature is 66.92–70.16°F (19.4–21.2°C). Fecundity is 306,578–1,162,920 eggs, depending on the size of the adult female.

conservation status

Not listed by IUCN.

significance to humans

One of the world's most important aquaculture species. Also used for weed control in rivers, fish ponds, and reservoirs.


Upper mouth

Culter alburnus

family

Cyprinidae

taxonomy

Culter alburnus Basilewsky, 1855, northern China.

other common names

English: Whitefish, lookup.

physical characteristics

Size moderate to large, 5.9–25.6 in (15–65 cm) in body length. Body long, compressed. Dorsal straight, abdomen curved. Belly is keeled from ventral base to anus. Snout blunt. Mouth extremely superior, almost vertical. Barbels absent. Pharyngeal teeth sharp, in three rows. Gill rakers long, 24–28. Dorsal fin short, with 3 unbranched, 7 branched rays; last unbranched ray is spine-like. Anal fin long, with 3 unbranched, 21–24 branched rays. Scales small. Lateral line complete, with 80–92 scales. Air bladder has 3 chambers. Back dark gray, lower sides and belly silver-white. Fins gray.

distribution

East Asia from Amur River to the Pearl River, and into northern Vietnam.

habitat

Rivers and floodplain lakes with aquatic macrophytes and slow-running water.

behavior

Often lives in middle and upper parts of water bodies in small groups. Swims fast and likes to leap.

feeding ecology and diet

Carnivorous. Feeds on zooplankton, insects, and small fishes.

reproductive biology

Males mature in the second, females in third year of life in the Yangtze River. Spawning occurs in mid-June in rivers or in shallow areas of lakes. Eggs are slightly attached to aquatic plants and may be detached and sink to the bottom due to wave movements. Fecundity varies from 51,490 to 532,350 eggs.

conservation status

Not listed by IUCN.

significance to humans

An important food fish in the floodplain area of China.


Common carp

Cyprinus carpio

family

Cyprinidae

taxonomy

Cyprinus carpio Linnaeus, 1758, Europe.

other common names

English: Carp, German carp, European carp, mirror carp, leather carp, leatherback, German bass.

physical characteristics

Size moderate to large, usually 11.8–15.74 in (30–40 cm) in body length. Body robust, compressed laterally. Snout long; mouth of moderate size reaching to below nostril. Two barbels on each side of upper jaw, smaller one from edge of snout, larger one near corner of mouth. Pharyngeal teeth in three rows; larger teeth molarlike. Gill rakers 21–27. Dorsal fin long, 4 spines, 15–23 branched rays; anal fin short, 3 spines, 5 branched rays. Back of last dorsal and anal spines serrated. Lateral line complete, with 32–41 scales. The usual longevity of the carp is 9–15 years; maximum observed longevity is 47 years. Brassy olive above, lower sides golden yellow; belly yellow-white. Basal half of caudal and anal fins often reddish; stronger coloration in adults.

distribution

Native to Asia from the Amur River to North Vietnam. It was carried to Europe just before and after the beginning of the common era. Its introduction to the American continent took place during the first half of the nineteenth century. By now it has been transplanted all over the world.

habitat

Lives in a wide variety of habitats, including ponds, lakes, streams, and large rivers. It can tolerate a very low concentration of oxygen and high salinity. Normally, it prefers shallow, warm waters with aquatic plants over cold, small streams with fast-running water.

behavior

Usually live in lower part or bottom of waters. In spring and autumn, they form schools. Though they need not migrate to rivers for reproduction, some fish can swim very long distances (up to 1,012 mi [1,629 km]).

feeding ecology and diet

Typically omnivorous and a benthic feeder. Food diet includes macrophytes, detritus and algae, molluscs, aquatic insects and their larvae, minute crustaceans, and small fishes.

reproductive biology

Males mature usually by the second year of life in Asia, third or fourth year in Europe. Females require an additional year for maturation. Spawning may occur when water temperature reaches 64.4°F (18°C). Another prerequisite for spawning is

the vegetation. Flood waters usually stimulate spawning. Spawning groups are composed of one female and one or more males. The males initiate the spawning act by repeatedly pushing their heads against the body of the female. On stimulation by the males, the female responds by raising her caudal peduncle and tail. Her tail lashes violently, and as she propels herself forward, she scatters the eggs over the vegetation. Simultaneously, the males come along the side of the female with their tail region proximate to the female genital opening and, by violent movements of their tail region, discharge their milts. The eggs are released gradually, in batches of 3–4, within a period of 3–4 days if the weather is good, or 2 to 3 weeks if spawning is interrupted by cold, cloudy, or windy spells. The eggs are attached to the vegetation and hatch after 2.5 to 3 days (water temperature 68–77°F [20–25°C]). For the first two days after hatching, the larvae stay on the grass quietly. On the third day, their air-bladders begin to get air. On the fourth day, the yolk-sac is nearly gone and the larvae begin to feed. The period of planktonic feeding is short; juveniles take invertebrate food from the bottom after reaching a length of 0.79 in (2 cm). Forty days later, with the body covered with scales and barbels appearing, the fish look very much like adults. Fecundity varies from 59,000 to 1,579,000 eggs per individual.

conservation status

Listed as Data Deficient by the IUCN. Due to artificial hybridization and transplantation, the genetic resources of common carp have been seriously damaged. Many different local varieties (e.g., red carp, glass carp) have been contaminated genetically.

significance to humans

This is the earliest domesticated fish species. Ancient Chinese began to culture the common carp around 200 b.c. As this species is considered a symbol of happiness and good fortune in China, it is still common as wedding gift, particularly in rural areas. The Japanese colored carp, koi, had its origin in Japan between a.d. 794 and 1184. It is now one of the most common ornamental fishes in the world.

Some local varieties are important as a source of food, while others are important in the aquarium trade. The common carp is also an important game fish.


Zebrafish

Danio rerio

family

Cyprinidae

taxonomy

Cyprinus rerio Hamilton, 1822, Kosi River, Utter Pradesh, India.

other common names

English: Zebra danio, striped danio; German: Zebrabärbling.

physical characteristics

Small fish, rarely grows beyond 1.97–2.36 in (50–60 mm) in length. Body slender, slightly compressed. Two pairs of barbels: rostral barbels extend to anterior margin of orbit; maxillary barbels end at about middle of opercle. Dorsal fin with 3 unbranched, 7 branched rays. Anal fin striped, with 3 unbranched, 10–12 branched rays. Lateral line incomplete or absent. Vertebrae 31–32. Body silvery, sometimes tinted with

gold, with five blue horizontal stripes on the sides. Stripes also present in the anal and caudal fins.

distribution

Native to tributaries of the Ganges River, along the Coromandel Coast of India, from Calcutta to Masulipatam, Bengal, Nepal, Pakistan, and Bangladesh. As aquarium fish and experimental animal, it has been introduced worldwide.

habitat

Slow-moving and still water bodies such as streams, canals, ditches, and ponds, particularly rice fields.

behavior

Very active, usually swimming in schools.

feeding ecology and diet

Feeds mainly on worms and small crustaceans. It also feeds on insect larvae and can be used for mosquito control.

reproductive biology

Matures in 4–6 months. Females are larger and have less vibrant coloration than males. Typically, spawning occurs in the early hours of the morning. Eggs are semiadhesive, relatively large, and released into open waters. Under experimental conditions, this species spawns at intervals of 1.9 to 2.7 days. However, spawning intervals in nature are typically much longer, varying from 5 days to several weeks. Between 21 and 60 eggs are released per spawning event. In captivity, the total number of eggs spawned is usually between 400 and 500. Eggs hatch approximately 20–48 hours after spawning. Larvae live from 48 to 72 hours on their yolk-sac provision.

conservation status

Not listed by IUCN.

significance to humans

Because of their small size, zebrafish are of no value as a food fish. However, they are very popular aquarium fish and also very important as experimental subjects for genomic study.


Black stick

Garra pingi

family

Cyprinidae

taxonomy

Garra pingi Tchang, 1929, Katin, Szechuan, China.

other common names

German: Pings Saugbarbe.

physical characteristics

Size small to moderate, normally 2.76–10.6 in (7–27 cm) in body length. Body slender, slightly cylindrical in the front, and compressed in the hind. Snout round, blunt. Mouth inferior, transverse. Lower lip specialized as disc. Barbels absent in adults. Pharyngeal teeth very small, in three rows. Gill rakers 36–44. Dorsal fin short, 2 unbranched, 9 branched rays; anal fin has 2 unbranched and 5 branched rays. Lateral line complete, with 48–52 scales. Dark black above, gray black on the lower sides; gray-white on belly. Bases of scales have black spots.

distribution

Upper reaches of the Yangtze, Pearl, and Mekong Rivers in Southeast Asia.

habitat

Lives in upper reaches of rivers with fast-running water and stony bottoms. Limited to warm waters.

behavior

Normally adheres to the stony bottom with the sucking disc formed by lower lip. Very active.

feeding ecology and diet

Mainly scrapes algae and fragmental plants, but also feeds on insect larvae.

reproductive biology

Little is known.

conservation status

Not listed by IUCN.

significance to humans

Used for food, but the production is very low.


Gudgeon

Gobio gobio

family

Cyprinidae

taxonomy

Cyprinus gobio Linnaeus, 1758, Britain and surrounding countries.

other common names

French: Gofi, goujon; German: Grässling; Spanish: Gobio.

physical characteristics

Small fish, length rarely exceeding 5.9 in (15 cm); maximum age 8 years. Body slender, round in front, compressed laterally toward the tail. Snout blunt. Mouth inferior. Barbels one pair. Pharyngeal teeth in 2 rows. Dorsal fin with 3 unbranched, 5–7

branched rays; anal fin with 3 unbranched, 6 branched rays. Lateral line complete, with 40–45 scales. Vertebrae 39–41. Brown-grey above, sides lighter, yellowish-white belly. On the sides there is a row of large, indistinct dark marks. Dorsal and tail fins are spotted.

distribution

Europe.

habitat

Fast-flowing rivers with sand or gravel bottoms; may also occur in still waters.

behavior

Often appear in large numbers. Normally active during the day, but if they are disturbed, in particular by predators, they can defer their activity to periods when light intensity is weak. They are capable of emitting squeaking sounds.

feeding ecology and diet

Bottom feeder. Usually active during summer months. Its diet includes insect larvae, mollusks, and freshwater shrimps.

reproductive biology

Matures in 2–3 years. The spawning time is from April to August, when temperatures are above 62.6°F (17°C). The fecundity is 2,500–6,500 eggs per individual.

conservation status

Not listed by IUCN.

significance to humans

The gudgeon's chief value is as bait for larger fish. Its flesh is tasty, but its small size reduces its value as food.


Silver carp

Hypophthalmichthys molitrix

family

Cyprinidae

taxonomy

Leuciscus molitrix Cuvier and Valencinnes, 1844, China.

other common names

English: Chinese schemer; French: Carpe argentée; German: Silberkarpfen, Tolstolob; Spanish: Carpa plateada.

physical characteristics

Size moderate to large, usually 11.8–15.74 in (30–40 cm) in body length. Body robust, compressed laterally. Keels from isthmus to anus on the belly. Head large. Snout blunt. Mouth terminal, wide and large. Barbels absent. Pharyngeal teeth in 1 row. Contains spiral gill-organ for feeding. Dorsal fin short, with 3 unbranched, 7 branched rays; anal fin long, with 3 unbranched 11–13 branched rays. Scales small. Lateral line complete, with 91–120 scales. Coloration is brassy olive above, and silver-white on lower sides and belly.

distribution

China and eastern Siberia. Introduced around the world for aquaculture and control of algal blooms.

habitat

Can live in standing or flowing waters such as ponds, lakes, and rivers. Prefers large waters with abundant plankton.

behavior

Active species well known for its habit of leaping clear of the water when disturbed. It often swims just beneath the water surface. Undergoes lake-river migration.

feeding ecology and diet

Typical filter feeder that lives near the surface and feeds on phytoplankton and microzooplankton with its big mouth and the gill organ.

reproductive biology

In Yangtze River, this fish matures in 3–4 years. Breeding season is from April to July. The fish migrate to middle or upper reaches of the river to breed. Spawning occurs near the surface of water. The eggs are semipelagic. Eggs and larvae float downstream to floodplain zones. The fecundity varies from 207,083 to 1,610,440 eggs.

conservation status

Not listed by IUCN.

significance to humans

The silver carp is an important food fish and has been introduced to many countries. It is among the 4 species of cyprinids whose world production in aquaculture exceeds 1 million tons per year. However, in some places it is mainly used for cleaning reservoirs and other waters where eutrophication is a problem.


Ningu

Labeo victorianus

family

Cyprinidae

taxonomy

Labeo victorianus Boulenger, 1901, Lake Victoria Nyanza, East Africa.

other common names

None known.

physical characteristics

Size small to moderate, maximum 15.75 in (40 cm) in standard length. Body long, slightly compressed. Snout profile smooth and rounded. Jaws with horny cutting ridge, with flap of skin in front of upper lip. Barbels hidden. Dorsal fin with 9–10 branched fin rays. Lateral line running along middle of the flank and the caudal peduncle; scales in lateral line 36–39. Olive dorsally, cream-colored ventrally. Dorsal, anal, and pelvic fins often orange-tipped.

distribution

East Africa: Lake Victoria (Nile drainage basin).

habitat

Shallow inshore waters and influent rivers.

behavior

Spends most of its life span in lakes, but migrates to spawn in flooded grasslands beside both permanent and temporary streams.

feeding ecology and diet

Feeds on detritus and algae. Also feeds on rotifers growing on the bodies of other fishes.

reproductive biology

Migrates to rivers to spawn in flood season.

conservation status

Not listed by IUCN. This species has been adversely affected by overfishing and predation by the introduced Nile perch.

significance to humans

Important food fish.


Common dace

Leuciscus leuciscus

family

Cyprinidae

taxonomy

Cyprinus leuciscus Linnaeus, 1758, Central Europe.

other common names

English: Dace; French: Acourcie, assée, aubour, gandoise; German: Hasel.

physical characteristics

Size small to moderate, length rarely exceeding 10.2 in (26 cm), maximum length 15.75 in (40 cm); maximum reported age is 16. Body long. Snout pointed. Mouth narrow, slightly inferior. Barbels absent. Pharyngeal teeth in 2 rows. Dorsal fin has 3 unbranched, 7–9 branched rays; anal fin has 3 unbranched, 8–9 branched rays. Lateral line complete, with 47–52 scales. Vertebrae 42–46. Dorsal part dark, sides silver, belly white.

distribution

Native to Europe and northern Asia. It has become widespread in Europe and gained access to Ireland as a bait fish.

habitat

Prefers upper reaches of rivers and especially clear, cool lakes with fast-flowing water and sand or gravel substrate.

behavior

Usually swims near the surface in large numbers, with large home range and localized feeding migrations.

feeding ecology and diet

Feeds on insects, worms, snails, and only rarely plants. It may feed all year, intensely so at dawn and dusk.

reproductive biology

Matures in 3–4 years. Reproduction occurs in March and April, when water temperature is 48.2–50°F (9–10°C), with single spawning. Eggs are pale yellow and attach to gravel and stones in shallow, flowing water. Fecundity for females is 6,500–9,500 eggs.

conservation status

Not listed by IUCN.

significance to humans

Not good as food fish because they are too small and bony, but they make good bait for larger fish.


Eurasian minnow

Phoxinus phoxinus

family

Cyprinidae

taxonomy

Cyprinus phoxinus 1758 Europe.

other common names

English: Common minnow; French: Amarante, arlequin, vairon; German: Blutelritze.

physical characteristics

Small fish, length rarely exceeding 3.94 in (10 cm); maximum age 6 years. Body slender, slightly compressed. Snout short and blunt. Mouth small, terminal. Barbels absent. Pharyngeal teeth in 2 rows. Gill rakers 7–8. Dorsal fin short, with 3 unbranched, 7 branched rays; anal fin with 3 unbranched, 7 branched rays. Scales small. Lateral line incomplete, with 32–41 scales, ending before anal origin. Coloration is brassy olive above, golden yellow on lower sides, and yellow-white on belly. Basal half of caudal and anal fins often reddish; stronger coloration in adults.

distribution

Eurasia, from British Isles and eastern Spain to eastern Siberia and Amur River.

habitat

Cold yet well-oxygenated waters (running or still) over gravel substrate, mainly in rivers and streams, occasionally in lakes and canals.

behavior

Often found in large numbers, never solitary. They may migrate upstream for spawning in shallow gravel areas.

feeding ecology and diet

Feeds on algae, plant debris, mollusks, crustaceans, zooplankton, and insect larvae. It may forage all day, and feeding takes place throughout the year.

reproductive biology

Matures in 2–3 years. The spawning times are mainly from June to July, with multiple spawning. Spawning takes place over gravel and weeds. Eggs are fixed on plants or stones. Fecundity is 200–1,000 eggs per female.

conservation status

Not listed by IUCN.

significance to humans

No commercial value but an important laboratory fish.


Fathead minnow

Pimephales promelas

family

Cyprinidae

taxonomy

Pimephales promelas Rafinesque, 1820, Lexington, Kentucky, United States.

other common names

English: Black-head minnow, rosy-red.

physical characteristics

Small fish, maximum 3.94 in (10 cm) in total length. Body moderately compressed. Snout short and blunt. Mouth sub-terminal. Scales deep, closely overlapping. Lateral line incomplete or nearly complete, with 43–44 scales. Both dorsal and anal fin with 7 branched rays. Olive to brown on the upper body and silvery white on the lower body with a dark mid-lateral stripe. Nuptial males tend to be larger than females with horny tubercles on the snout and a prominent pad of spongy wrinkled tissue on the nape. One variety with light orange color named rosy red.

distribution

Native to central North America, northeastern United States, and northeastern Mexico. It has been introduced widely throughout much of North America as a bait minnow.

habitat

Found in a wide variety of habitats in rivers, streams, lakes, and ponds, particularly in waters with abundant floating and submerged vegetation. It has a high tolerance for turbid waters, low oxygen, and high temperatures.

behavior

Shoaling species. Males are territorial in breeding season.

feeding ecology and diet

Feeds in soft bottom mud, taking a variety of items from algae and plant fragments to insect larvae and microscopic crustaceans.

reproductive biology

Matures by about six months of age. Spawning occurs from late May to early June when water temperatures exceed 60.8°F (16°C). In breeding season, a male develops dark coloration and breeding tubercles on his head, and a soft mucus-like pad on his nape. The male selects the nest site under an object such as a log, rock, or stick, and excavates the area around the object. He then defends it aggressively from all other fatheads except egg-laden females. The female enters the nest, turns upside down, lays her sticky eggs on the underside of the nest object, and leaves the nest. The male then fertilizes the eggs and guards the incubating eggs. He fans them with his fins and massages them with his back pad to keep them clean and well oxygenated. Other females may add eggs to the nest as the spawning season progresses. The male continues his care until all of the eggs hatch. Females produce clutches of eggs. Each clutch may contain 80–370 eggs. Most females probably spawn several clutches in a season. The embryos hatch in about 4–6 days.

conservation status

Not listed by IUCN.

significance to humans

Often sold as bait and in aquarium stores to be used as "feeder fish." Several countries report adverse ecological impact after introduction, such as causing the spread of enteric redmouth disease, which has infected wild and cultured trouts and eels. The fathead minnow was used in the past as a form of mosquito control in some places and is still widely used as a bio-assay subject.


Colorado pikeminnow

Ptychocheilus lucius

family

Cyprinidae

taxonomy

Ptychocheilus lucius Girard, 1856, Colorado River, California, United States.

other common names

English: Colorado squawfish.

physical characteristics

Largest cyprinid in North America, maximum 71 in (180 cm) in total length. Body slender, elongate, with long, depressed head. Maxillary reaching past anterior margin of the eye. Fins moderate, both dorsal and anal fins with 9 branched rays. Scales very small; lateral line very strongly decurved; lateral line scales 83–87. Color plain, dark above. Young always have a black caudal spot and a faint pale lateral band below a darker one.

distribution

North America, in the Colorado River drainage in Wyoming, Colorado, Utah, New Mexico, Arizona, Nevada, and California, from the United States to Mexico. Now mostly restricted to Utah and Colorado and extirpated from the southern portion of the range by the construction of large dams on the Colorado and Gila Rivers.

habitat

Juveniles utilize backwater and side channel areas with little or no current and silt or sand substrates. Adults inhabit medium to large rivers, with larger ones found in deep pools with a strong current flowing over rocky or sandy substrates.

behavior

Adults are largely solitary, except during spawning or during low flows that crowd them into reduced habitat.

feeding ecology and diet

Younger individuals feed primarily on insects and crustaceans, whereas older fish are piscivores, consuming only other fish.

reproductive biology

Spawns from early July through mid-August, after water temperatures have exceeded 64.4°F (18°C) for about a month. Preferred spawning sites are apparently gravel and cobble-bottomed riffles, where the interstitial spaces are free of organic matter and sediment. Newly hatched larvae drift downstream to quiet backwaters, where they grow rapidly and then return to the main-channel habitats when they are about 3 in (7.6 cm) long.

conservation status

Classified as Vulnerable by the IUCN. The near extinction of this species is due to a combination of factors, the most significant being those associated with water development projects that have altered stream morphology, flow patterns, temperatures, water chemistry, and silt loads of most major streams throughout the Colorado River basin. Also, several exotic species may prey upon and compete with Colorado pike-minnows, particularly juveniles. Finally, there have been several fish eradication projects that may have had a severe impact on local populations. A captive propagation is underway; reintroductions into the Salt and Verde drainages began in 1985.

significance to humans

This species used to be an important food fish, but now its population is too small to sustain such activities.


Tiger barb

Puntius tetrazona

family

Cyprinidae

taxonomy

Capoeta tetrazona Bleeker, 1855, Lahat, Palembang Province, Sumatra, Indonesia.

other common names

English: Green tiger barb, Sumatra barb, partbelt barb; German: Moosbarbe; Malay: Ikan baja.

physical characteristics

Small fish, maximum 2.76 in (7 cm) in total length. Body stocky, deep, and compressed. Mouth obtuse. Barbels absent. Dorsal fin with 8–9 branched rays, anal fin with 5 branched rays. Brilliantly colored. Dorsal brown to olive in color, flanks with a delicate reddish brown luster. Scales splendidly edged with shining gold. Body covered with four black vertical bars, with the first one passing through the eye, the second just anterior to the insertion of the dorsal fin, the third posterior to the dorsal, and the fourth passing through the caudal peduncle. Dorsal and anal fins blood-red; remaining fins more or less reddish. Ventral fins are occasionally black. Besides the traditional form, albino, black, and green morphs are also seen in the aquarium industry.

distribution

Southeast Asia: Sumatra and Borneo. Introduced widely and has been reared in several countries in facilities for breeding aquarium fishes.

habitat

Shallow, warm rivers and streams.

behavior

Lively shoaling fish. Aquarium specimens are notorious for their habit of picking at the fins of other fish.

feeding ecology and diet

Feeds on worms, small crustaceans, and plant matter.

reproductive biology

Matures between 9–12 months of age. Males are smaller and more brightly colored than females. Generally from 300 to 1,000 eggs are spawned. The eggs are large and yellowish, and the fry hatch within 36 hours.

conservation status

Not listed by IUCN.

significance to humans

Very popular as an aquarium fish.


Harlequin

Rasbora heteromorpha

family

Cyprinidae

taxonomy

Rasbora heteromorpha Duncker, 1904, Kuala Lumpur, Selangor, Malaysia.

other common names

English: Red rasbora; German: Keilfleckrasbora; Finnish: Kiilakylki; Russian: Rasbora krasnaya.

physical characteristics

Small fish, maximum 1.97 in (5 cm) in total length. Lateral line incomplete. Anterior part silver in color. Starting beneath the dorsal fin running to the tail, individuals are marked with a blackish blue triangular-shaped patch. This patch is slightly rounded at the bottom and ends in an extended tip in males but is straight in females. Eyes have a bright red glow. Dorsal fin vivid red with a yellow tip; tip of caudal fin bright red; inner rays yellow.

distribution

Thailand to Sumatra, Indonesia.

habitat

Small waters in rainforests.

behavior

Shoaling species.

feeding ecology and diet

Feeds on worms, crustaceans, and insects.

reproductive biology

The usual site for spawning is the underside of a broad-leafed aquatic plant. Females deposit their eggs rather than merely scattering them in the water.

conservation status

Not listed by IUCN.

significance to humans

Very popular as an aquarium fish.


Dagaa

Rastrineobola argentea

family

Cyprinidae

taxonomy

Neobola argentea Pellegrin, 1904, Lake Victoria, Africa.

other common names

English: Silver cyprinid, mukene, sardine; German: Viktoria-Sardine; Swahili: Omena.

physical characteristics

Small fish, rarely reaching a length greater than 3.15 in (8 cm) in standard length. Body slender, compressed. Barbels absent. Cheeks covered by thin suborbital bones. Lateral line low on the body and running along lower part of caudal peduncle; scales in lateral line 42–56. Body silver-white with an overall nacreous sheen. Caudal fin yellow. White-blue stripe along the middle of the body side.

distribution

East Africa: Lakes Victoria and Kyoga and Nile River drainage basin.

habitat

Found inshore and offshore. Adults stay near the bottom during the day and near the surface at night.

behavior

Shoaling species.

feeding ecology and diet

Feeds on zooplankton and surface insects.

reproductive biology

Matures in the second year of life and spawns near the shore. Juvenile fish migrate away from the shore after spending their larval stage in shallow areas.

conservation status

Not listed by IUCN.

significance to humans

One of the three most important commercial species in Lake Victoria. It is a cheap source of protein food for direct human consumption and also an important food item for larger fishes in the lake.


Rosy bitterling

Rhodeus ocellatus

family

Cyprinidae

taxonomy

Pseudoperilampus ocellatus Kner, 1866, Shanghai, China.

other common names

German: Hongkong Bitterling.

physical characteristics

Small fish, body length usually shorter than 2.76 in (7 cm). Body very deep, oval-shaped, compressed laterally. Snout short and blunt. Mouth small, terminal. Barbels absent. Pharyngeal teeth compressed, in 1 row. Gill rakers 10–14. Dorsal fin moderate, with 3 unbranched, 10–12 branched rays; anal fin with 3 unbranched, 9–12 branched rays. Lateral line incomplete, with 2–6 scales. Olive green above, lower sides white. Males very colorful, with a red dot on the base of caudal fin; one horizontal blue stripe from below dorsal origin to caudal base; two transverse blue bands above shoulder area; and eyes that are reddish on their upper halves.

distribution

China and Vietnam. Has been introduced into Japan.

habitat

Shallow lakes, ponds, and streams. Prefers clear, slow-running water, especially when it includes aquatic plants.

behavior

Normally found in small groups near the shore. In breeding season, males are territorial.

feeding ecology and diet

Pelagic feeder, taking zooplankton, algae, and fragmental plants.

reproductive biology

Matures in the first year, spawns in the second year from April to May. During spawning, the male finds a mussel, then attracts a female to the site. They both swim around the mussel, and the female next lays eggs into the mussel with a tube (ovipositor). The male then releases sperm, which is carried by the current into the gill chamber of the mussel, where it fertilizes the eggs. The eggs hatch after one day, but the larvae stay in the gill chamber for about 20 days. When the air-bladders fill with air and the egg yolks are nearly gone, the larvae swim out of the gill chamber to live independently.

conservation status

Not listed by IUCN.

significance to humans

Bitterlings are interesting aquarium fishes because of their beautiful color and special breeding mode. They can be used to control mosquitos. In some places, they are used as indicators of environmental conditions, since they are sensitive to pollution.


Rudd

Scardinius erythrophthalmus

family

Cyprinidae

taxonomy

Cyprinus erythrophthalmus Linnaeus, 1758, northern Europe.

other common names

French: About, gardon rouge; German: Rotfeder; Spanish: Gardí; Russian: Krasnoperka.

physical characteristics

Size moderate to large, maximum 20 in (51 cm) in total length. Body stocky and compressed. Mouth narrow, directed forward with the lower lip protruding. Belly strongly keeled between ventral fins and anus. Dorsal fin with 8–9 branched rays. Anal fin with 9–12 branched rays. Color brown-olive dorsally, sometimes with a brassy sheen; flanks brassy colored; belly silver-white.

Ventral, anal, and lower part of caudal fins are a brilliant golden-red. Males develop spawning tubercles.

distribution

Widespread in Europe and middle Asia in the basins of the North, Baltic, Black, Caspian (from Emba, Ural, and Volga to the rivers of the southern coast) and Aral Seas. Introduced to several countries.

habitat

Dwells mainly in waters with a soft bottom and strong plant growth, especially where there are reedy margins including lakes, rivers, marshlands, canals, and ponds.

behavior

Shoaling species.

feeding ecology and diet

Omnivorous. Feeds on invertebrates (including insect larvae and adults) and plants; particularly partial to insects from the water surface.

reproductive biology

Matures after three to four years of age and spawns from mid-May to early June. The eggs adhere to water plants. The average rudd produces 108,000 to 211,000 eggs per kilogram of body weight. The young, which hatch after six to eight days, are no larger than a pinhead and spend the first part of their lives sheltering in shoals in the water margins. As the fry grow larger, they move out into deeper water and begin to feed on insects.

conservation status

Although not listed by the IUCN, this species is threatened due to the introduction of other species.

significance to humans

Cultured as food in some countries; also used as bait for fishing. Although adults actively feed on macrophytes present in abundance in the environment, they are not an effective species for the biological clearing of weeds. Several countries report adverse ecological effects after introduction.


No common name

Schizothorax prenanti

family

Cyprinidae

taxonomy

Oreinus prenanti Tchang, 1930, Omei Mountain, Szechuan, China.

other common names

None known.

physical characteristics

Size moderate, often 5.9–7.87 in (15–20 cm) in body length. Body long, slightly compressed. Snout somewhat pointed. Mouth inferior, transverse. Sharp horny edge on lower jaw. Lower lip papillae. Barbels 2 pairs, length similar to eye diameter. Pharyngeal teeth are sharp and in three rows. Gill rakers 14–23. Dorsal fin short, 3 unbranched, 8 branched rays; anal fin 3 unbranched, 5 branched rays. Back of last unbranched fin ray weakly serrated. Scales small. Lateral line complete, with 90–109 scales. Two rows of large scales along the anus. Brown or blue-brown above, sometimes with black spots; belly light yellow. Fins also light yellow.

distribution

Upper reaches of the Yangtze River in China. However, the group Schizothoracin, adapted to the plateau environment, is mainly distributed in and around the Tibetan Plateau.

habitat

Lives on the bottom of large rivers. Normally stays in succession areas between swift- and slow-running waters. Prefers low temperatures.

behavior

Populations of this species mainly stay in large rivers, but some migrate to tributaries with swift waters to spawn eggs.

feeding ecology and diet

Normally uses the sharp horny edge on its lower jaw to scrape algae. Its diet also includes insects.

reproductive biology

Males mature in the third, females in the fourth year of life. Spawning occurs from March to April. Eggs are slightly adhesive, staying in apertures between stones to hatch. Fecundity varies from 20,000 to 40,000 eggs per individual.

conservation status

Not listed by IUCN.

significance to humans

Important food fish in local areas and very expensive.


Tench

Tinca tinca

family

Cyprinidae

taxonomy

Cyprinus tinca Linnaeus, 1758, European lakes.

other common names

French: Aiguillons, tanche; German: Alia.

physical characteristics

Size moderate, normally 11.8 in (30 cm) in length, and rarely exceeding 23.6 (60 cm), and 3.97 lbs (1.8 kg) in weight; maximum age 14 years. Body robust, slightly compressed. Snout somewhat blunt. Mouth moderate, terminal, and oblique, with thick lips. Barbels 1 pair, very short. Pharyngeal teeth compressed, in 1 row. Gill rakers short, 12–14. Dorsal fin short, with 3 unbranched, 8 branched rays; anal fin with 3 unbranched, 7 branched rays. Scales small. Lateral line complete, with 100–105 scales. The caudal peduncle is characteristically deep and short. Skin thick and very slimy. Olive green above, dark green or almost black, with golden reflections, on ventral surface; the fins are always dark; eyes orange-red.

distribution

Eurasia, found throughout Europe to northwestern China.

habitat

Warm lakes and pools with weed and mud bottoms. It can tolerate low oxygen levels. In winter, this fish stays in the mud without feeding itself.

behavior

Tench have limited home range. They are mostly solitary, occasionally occurring in small groups.

feeding ecology and diet

Omnivorous. Feeds on bottom invertebrates and aquatic insect larvae. Young tench also feed on algae. Foraging is often active at dawn and dusk.

reproductive biology

Matures in 3–5 years. Breeds in shallow water among dense vegetation, laying numerous sticky green eggs in the period from May to August. After hatching, the larvae remain attached to plants for several days. The fecundity is 300,000–400,000 eggs per kilogram of body weight.

conservation status

Not listed by IUCN.

significance to humans

Because its flesh is highly esteemed, the tench has considerable value, although it grows very slow. A golden color variety is a popular ornamental pond fish.


Smallscale yellowfin

Xenocypris microlepis

family

Cyprinidae

taxonomy

Xenocypris microlepis Bleeker, 1871, Yangtze River, China.

other common names

English: Fine-scaled yellowfin; Russian: Melkocheshuinyi zheltoper.

physical characteristics

Size moderate, normally 4.67–8.8 in (11.9–22.4 cm) in body length; maximum 27.56 in (70 cm) in total length. Body long and compressed. Snout short and blunt. Mouth inferior, with sharp horny edge on the lower jaw. Barbels absent. Pharyngeal teeth in three rows; teeth in the main row compressed. Gill rakers 36–48. Dorsal fin short, with 3 unbranched, 7 branched rays; anal fin with 3 unbranched, 10–14 branched rays. Scales small. Lateral line complete, with 72–84 scales. Back gray-black, lower sides and belly silver-white. Dorsal fin dark; pectoral and ventral fins gray-white; anal and caudal fins orange-yellow.

distribution

East Asia from Amur River to Yellow River, Yangtze River, and Pearl River.

habitat

Large rivers and lakes. Prefers clear waters with vegetation.

behavior

Congregates in schools in winter in deep waters. Moves to shore to catch food in spring. Migrates to upper reaches of rivers to breed.

feeding ecology and diet

Normally uses the sharp horny edge on its lower jaw to scrape algae on the bottom. Its diet includes algae, fragmental plants, and insect larvae.

reproductive biology

Matures in the second year of life. Spawning occurs from April to June. When floods occur and the water level rises rapidly, mature fish swim against the current and spawn in areas with fast-flowing water and stony bottoms. Eggs are attached to stones and hatch there. Fecundity varies from 42,000 to 292,000 eggs.

conservation status

Not listed by IUCN.

significance to humans

Important food fish. Also used to keep fishery ponds clean.


Resources

Books

Becker, G. C. Fishes of Wisconsin. Madison: The University of Wisconsin Press, 1983.

Chen, Y., ed. Fauna Sinica, Osteichthys: Cypriniformes, Part II. Beijing: Science Press, 1998.

Department of Ichthyology, Hubei Institute of Hydrobiology. Fishes of the Yangtze River. Beijing: Science Press, 1976.

Nelson, J. S. Fishes of the World, 3rd ed. New York: John Wiley & Sons, 1994.

Mayden, R. L., ed. Systematics, Historical Ecology and North American Freshwater Fishes. Stanford: Stanford University Press, 1992.

Wheeler, A. The Fishes of the British Isles and North-west Europe. London: Macmillan, 1969.

Winfield, I., and J. Nelson, eds. Cyprinid Fishes: Systematic Biology and Exploitation. New York: Chapman & Hall, 1991.

Yue, P., ed. Fauna Sinica, Osteichthys: Cypriniformes, Part III. Beijing: Science Press, 2000.

Periodicals

Briolay, J., N. Galtier, R. M. Brito, and Y. Bouvet. "Molecular Phylogeny of Cyprinidae Inferred from Cytochrome bDNA Sequences." Molecular Phylogenetics and Evolution 9 (1998): 100–108.

Chen, X., P. Yue, and R. Lin. "Major Groups Within the Family Cyprinidae and Their Phylogenetic Relationships." Acta Zootaxonomica Sinica 9 (1984): 424–440.

Gilles, A., G. Lecointre, A. Miquelis, M. Loerstcher, R. Chappaz, and G. Brun. "Partial Combination Applied to Phylogeny of European Cyprinids Using the Mitochondrial Control Region." Molecular Phylogenetics and Evolution 19(2001): 22–33.

Gilles, A., G. Lecointre, E. Faure, R. Chapaz, and G. Brun. "Mitochondrial Phylogeny of the European Cyprinids: Implications for Their Systematics, Reticulate Evolution and Colonization Time." Molecular Phylogenetics and Evolution 10 (1998): 132–143.

Gosline, W. A. "Unbranched Dorsal-fin Rays and Subfamily Classification of the Fish Family Cyprinidae." Occasional Papers of the Museum of Zoology, University of Michigan 684(1978): 1–21.

Harris P. M., and R. L. Mayden. "Phylogenetic Relationships of Major Clades of Catostomidae (Telesotei: Cypriniformes) as Inferred from Mitochondrial SSU and LSU rDNA sequences." Molecular Phylogenetics and Evolution 20 (2001): 225–237.

Liu, H., C. S. Tzeng, and H. Y. Teng. "Sequence Variations in the mtDNA Control Region and Their Implications for the Phylogeny of the Cypriniformes." Canadian Journal of Zoology 80 (2002): 596–581.

Zardoya, R., and I. Doadrio. "Molecular Evidence on the Evolutionary and Biogeographical Patterns of European Cyprinids." Journal of Molecular Evolution 49 (1999): 227–237.

Huanzhang Liu, PhD